Infrared photodetectors based on graphene metal nano clusters

In this article, we have designed an improved structure for gold nonamer nanodisk arrays on graphene as a photodetector to enhance the light absorption for optical communication spectrum. Effects of different structural parameters on absorption spectrum have been investigated, numerically. We have shown that light absorption in graphene-based detectors can be manipulated by tuning cluster size, thickness, inter disks gap distance, graphene position, and the number of graphene layers. By changing the radius of central and peripheral disks, we have shown that the Au nonamer on top of graphene is able to support strong sub- and superradiant plasmon resonances because of its unique geometrical features and a second absorption peak is generated. This additionally generated absorption peak is more suitable for application in 1550 nm nanostructure photodetectors.